深厚软土CFG桩复合地基沉降计算方法对比分析

论文结合京沪高速铁路李窑试验段，对比分析了深厚软土CFG桩复合地基加固区、下卧层附加应力和沉降的不同计算方法，并对现场案例的加固区和下卧层在不同计算方法的沉降计算结果进行了分析研究。结果表明：（1）Boussinesq解能够准确计算复合地基加固区附加应力，Mindlin-Geddes解能够准确计算复合地基下卧层附加应力；（2）面积加权法能够有效计算复合地基加固区沉降；（3）通过线性叠加，计算复合地基下卧层附加应力，能够有效考虑群桩下的复合地基下卧层沉降；（4）由面积加权法和弹性力学法计算得出加固区的沉降量接近，而远大于桩土模量比法计算结果；（5）复合地基置换率相同的情况下，随着桩数的增加下卧层的沉降随之增加。

COMPARED AND ANALYSIS CALCULATION METHOD OF CFG PILE COMPOSITE FOUNDATION ON SETTLEMENT ON DEEP AND SOFT SOIL

This paper combine Liyao test section of Beijing-Shanghai high-speed rail, compared and analyzed deep and soft soil CFG pile composite foundation various additional stress and settlement calculation methods in reinforcement zone and substratum. The results show:(1) Boussinesq solution can accurately calculate additional stress of reinforcement zone in composite foundation, Mindlin-Geddes solution can accurately calculate additional stress of the substratum in composite foundation.(2) Area weighted method can effectively calculate additional settlement of reinforcement zone in composite foundation.(3) the additional stress of substratum in composite foundation calculated by linear superposition that the method can effectively consider settlement of substratum in composite foundation under pile group.(4) There is very similar for the results between area weighted method and elasticity caculated method, and much larger than the pile-soil modulus ratio method.(5) the settlement underlying layer of composite foundation would increase with the increase of the piles number in the same replacement rate.